Fabrication of Ordered SnO2 Nanostructures with Enhanced Humidity Sensing Performance

Abstract

Ordered SnO2 nanostructures were prepared as humidity sensors by nanosphere lithography with the magnetron sputtering technique. The X-ray diffraction patterns of SnO2 nanostructures show that all intense diffraction peaks correspond to the crystallographic planes of SnO2. The Atomic Force Microscope (AFM) mage shows that these SnO2 nanostructures exhibited a classic honeycomb structure. The resistance of this sensor was measured to show that the resistance of the sensor decreases with an increase from lower relative humidity (RH) to higher RH. Additionally, the longest response/recovery time was 32 s/42 s for 11–96% RH. The hysteresis for the SnO2 nanostructure sensor was <5%.

Contact-Based Methods for Measuring Respiratory Rate

“…Vfalse(RHfalse) is the voltage output, ifalse(RHfalse) is the current output. The capacitive sensors picture is adapted from [112]; the resistive sensors picture is from [113]; the nanocrystals and nanoparticles sensors image is from [114]; the fiber-optic humidity sensors picture is adapted from [115].…”

Recent Advances in Graphene-Based Humidity Sensors

“…According to the change of the physical parameters after interacting with water molecules, humidity sensors can be categorized into many types, such as the capacitive type, resistive type, impedance type, optic-fiber type, quartz crystal microbalance (QCM) type, surface acoustic wave (SAW) type, resonance type, and so on [3]. Many materials sensitive to water molecules have been developed as sensing materials in humidity sensors, including ceramics, such as Al 2 O 3 , SiO 2 , and spinel compounds [2]; semiconductors, such as TiO 2 [5,6], SnO 2 [7,8,9,10], ZnO [11,12,13,14], In 2 O 3 , Si [15], and perovskite compounds [16,17]; polymers, such as polyelectrolytes [18,19], conducting and semiconducting polymers [20], and hydrophilic polymers [21,22,23,24]; 2D materials, such as MoS 2 [25,26,27], WS 2 [28,29,30], and black phosphorus [31,32,33,34]; and carbon materials, such as porous carbon [35], carbon nanotubes [36,37], and graphene [38,39].…”

The synthesis of a Cu0.8Zn0.2Sb2–polyacrylamide nanocomposite by frontal polymerization for moisture and photodetection performance

“…In recent years to minimize the wastage of energy and improve the energy-saving practices, photoconduction has been studied for different nanomaterials. 26,28,30 The results of a literature survey based on other metal oxides used as humidity sensors is shown in Table 1: [31][32][33][34][35][36][37][38] Here, in the method described in the present manuscript, a ternary metal-doped AAm composite was used for photoconduction behaviour and as a humidity sensor for the measurement of moisture. Previous investigations were focussed only on single metal-doped complexes but here a stable ternary system for humidity sensing is reported for the first time.…”